Create a single 16:9 cinematic underwater exploration key art still. Show a marine biologist in a sleek wetsuit swimming through vibrant coral reefs near the Great Barrier Reef, approaching an ancient shipwreck covered with coral and marine growth. In the foreground, the diver carefully retrieves a mysterious ancient artifact from the wreck while schools of colorful tropical fish swirl around and a curious non-aggressive shark glides in the mid-distance. Use cinematic underwater lighting, sun rays piercing blue water, floating particles, realistic marine life, rich coral colors, adventurous but calm mood, 4K film look, and a wide composition where the diver, shipwreck, artifact, fish, and shark are all clear. Avoid logos, source-site branding, watermark inside the artwork, readable text, QR codes, URLs, UI chrome, gore, unsafe animal attack, real-world conservation claim text, and disrespectful handling of cultural artifacts.